Function appendNativeReasoningToBlocks

cli/src/utils/block-operations.ts:290–323

(
  blocks: ContentBlock[],
  text: string,
)

 * Similar to how appendTextToRootStream handles reasoning for root.
 */
const appendNativeReasoningToBlocks = (
  blocks: ContentBlock[],
  text: string,
): ContentBlock[] => {
  if (!text) {
    return blocks
  }

  const nextBlocks = [...blocks]
  const lastBlock = nextBlocks[nextBlocks.length - 1]

  // If last block is already an open native reasoning block, append to it
  // Only append if it's a native reasoning block (thinkingOpen === undefined),
  // not a closed one or a <think> tag block
  if (isNativeReasoningBlock(lastBlock) && lastBlock.type === 'text') {
    const updatedBlock: ContentBlock = {
      ...lastBlock,
      content: lastBlock.content + text,
    }
    nextBlocks[nextBlocks.length - 1] = updatedBlock
    return nextBlocks
  }

  // Create a new native reasoning block
  const newBlock: ContentBlock = {
    type: 'text',
    content: text,
    textType: 'reasoning',
    thinkingCollapseState: 'preview',
    thinkingId: generateThinkingId(),
  }

  return [...nextBlocks, newBlock]
}

/**
 * Checks if a block is a native reasoning block (not from <think> tags).